WC particles reinforced CoCrFeNiMo high-entropy alloy(HEA)composite coatings were prepared on Cr12MoV steel successfully by laser cladding technology to improve the wear resistance of substrates.Effect of WC content o...WC particles reinforced CoCrFeNiMo high-entropy alloy(HEA)composite coatings were prepared on Cr12MoV steel successfully by laser cladding technology to improve the wear resistance of substrates.Effect of WC content on microstructure and wear property of the composite coatings was studied in detail.Large numbers of carbides with four main types:primary carbide crystals,eutectic structures,massive crystals growing along the periphery of the remaining WC particles and incompletely fused WC particles,were found to exist in the WC/CoCrFeNiMo composite coatings.With increasing WC content,the microhardness of coatings is gradually improved while the average friction coefficients follow the opposite trend due to solid solution strengthening and second phase strengthening effect.The maximum microhardness and minimum friction coefficient are HV_(0.2)689.7 and 0.72,respectively,for the composite coating with 30 wt.%WC,the wear resistance of the substrate is improved significantly,the wear mechanisms are spalling wear and abrasive wear due to their high microhardness.展开更多
To understand the specific behaviors of coastal coral sand slope foundations,discrete element method(DEM)was employed to examine the effect of breakable particle corners on the performance of coral sand slope foundati...To understand the specific behaviors of coastal coral sand slope foundations,discrete element method(DEM)was employed to examine the effect of breakable particle corners on the performance of coral sand slope foundations under a strip footing,from macro to micro scales.The results demonstrate that the bearing characteristics of coral sand slope foundations can be successfully modeled by utilizing breakable corner particles in simulations.The dual effects of interlocking and breakage of corners well explained the specific shallower load transmission and narrower shear stress zones in breakable corner particle slopes.Additionally,the study revealed the significant influence of breakable corners on soil behaviors on slopes.Furthermore,progressive corner breakage within slip bands was successfully identified as the underling mechanism in determining the unique bearing characteristics and the distinct failure patterns of breakable corner particle slopes.This study provides a new perspective to clarify the behaviors of slope foundations composed of breakable corner particle materials.展开更多
生成式人工智能(AIGC)的快速崛起,掀起“人工智能+”赋能各行各业的浪潮,对会计领域的研究提供了新思路。由于财会行业要求高精确性与可解释性,而大语言模型存在着模型幻觉与决策黑箱,使得大模型应用于财会领域仍存在较大阻碍,构建财会...生成式人工智能(AIGC)的快速崛起,掀起“人工智能+”赋能各行各业的浪潮,对会计领域的研究提供了新思路。由于财会行业要求高精确性与可解释性,而大语言模型存在着模型幻觉与决策黑箱,使得大模型应用于财会领域仍存在较大阻碍,构建财会知识图谱成为弥补大语言模型不足的有力工具。基于此,文章调用GPT-4o mini API,利用提示词工程(Prompt)与智能体(Agent)思路方法进行自动化知识抽取,构建中国会计准则知识图谱,从模式层提取财会实体与实体间复杂的勾稽关系,为大模型优化微调提供数据层支持。图谱构建结果表明,GPT-4o mini能够成功从大量财务数据中提取丰富的知识五元组,并基于此构建财会知识图谱。最终,通过Neo4j技术实现知识图谱的可视化和查询功能。本研究证明大语言模型构建财会知识图谱具备可行性,能够显著提高知识图谱构建效率,为知识图谱的优化构建提供新思路,也为未来知识图谱融入大模型、优化模型性能提供基底数据支撑。展开更多
通过自主搭建的石油焦颗粒堆积床导热性能测试实验装置开展了热态实验,探究了石油焦颗粒堆积床在不同粒度与升温速率下料层内外温度的变化规律。基于计算传热学原理,构建了圆柱管径向传热正问题模型,利用Levenberg-Marquardt算法反推导...通过自主搭建的石油焦颗粒堆积床导热性能测试实验装置开展了热态实验,探究了石油焦颗粒堆积床在不同粒度与升温速率下料层内外温度的变化规律。基于计算传热学原理,构建了圆柱管径向传热正问题模型,利用Levenberg-Marquardt算法反推导热系数,并与经典的等效导热系数模型(Bruggeman模型,Maxwell-Garnett模型,Kunii and Smith模型和Zehner-Bauer-Schlünder模型)进行了对比。结果表明,料层壁面与中心的温差随温度升高先增后减,随升温速率增大而增大,且随颗粒粒度减小而增加。基于导热反问题方法,获得了石油焦颗粒堆积床导热系数λ与温度T和等效粒径dp的数学关系式。引入等效粒度系数φ修正后的Kunii and Smith模型计算的导热系数及导热反问题求解的导热系数均与实验数据吻合度较高。研究成果可为罐式炉内石油焦堆积床传热行为的深入剖析提供重要的理论支撑。展开更多
基金Project(2021YFC2801904)supported by the National Key R&D Program of ChinaProject(KY10100230067)supported by the Basic Product Innovation Research Project,China+3 种基金Projects(52271130,52305344)supported by the National Natural Science Foundation of ChinaProjects(ZR2020ME017,ZR2020QE186)supported by the Natural Science Foundation of Shandong Province,ChinaProjects(AMGM2024F11,AMGM2021F10,AMGM2023F06)supported by the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai,ChinaProject(KY90200210015)supported by Leading Scientific Research Project of China National Nuclear Corporation(CNNC),China。
文摘WC particles reinforced CoCrFeNiMo high-entropy alloy(HEA)composite coatings were prepared on Cr12MoV steel successfully by laser cladding technology to improve the wear resistance of substrates.Effect of WC content on microstructure and wear property of the composite coatings was studied in detail.Large numbers of carbides with four main types:primary carbide crystals,eutectic structures,massive crystals growing along the periphery of the remaining WC particles and incompletely fused WC particles,were found to exist in the WC/CoCrFeNiMo composite coatings.With increasing WC content,the microhardness of coatings is gradually improved while the average friction coefficients follow the opposite trend due to solid solution strengthening and second phase strengthening effect.The maximum microhardness and minimum friction coefficient are HV_(0.2)689.7 and 0.72,respectively,for the composite coating with 30 wt.%WC,the wear resistance of the substrate is improved significantly,the wear mechanisms are spalling wear and abrasive wear due to their high microhardness.
基金Projects(51878103,52208370)supported by the National Natural Science Foundation of ChinaProject(cstc2020jcyjcxtt X0003)supported by the Innovation Group Science Foundation of the Natural Science Foundation of Chongqing,ChinaProject(2022CDJQY-012)supported by the Fundamental Research Funds for the Central Universities,China。
文摘To understand the specific behaviors of coastal coral sand slope foundations,discrete element method(DEM)was employed to examine the effect of breakable particle corners on the performance of coral sand slope foundations under a strip footing,from macro to micro scales.The results demonstrate that the bearing characteristics of coral sand slope foundations can be successfully modeled by utilizing breakable corner particles in simulations.The dual effects of interlocking and breakage of corners well explained the specific shallower load transmission and narrower shear stress zones in breakable corner particle slopes.Additionally,the study revealed the significant influence of breakable corners on soil behaviors on slopes.Furthermore,progressive corner breakage within slip bands was successfully identified as the underling mechanism in determining the unique bearing characteristics and the distinct failure patterns of breakable corner particle slopes.This study provides a new perspective to clarify the behaviors of slope foundations composed of breakable corner particle materials.
文摘生成式人工智能(AIGC)的快速崛起,掀起“人工智能+”赋能各行各业的浪潮,对会计领域的研究提供了新思路。由于财会行业要求高精确性与可解释性,而大语言模型存在着模型幻觉与决策黑箱,使得大模型应用于财会领域仍存在较大阻碍,构建财会知识图谱成为弥补大语言模型不足的有力工具。基于此,文章调用GPT-4o mini API,利用提示词工程(Prompt)与智能体(Agent)思路方法进行自动化知识抽取,构建中国会计准则知识图谱,从模式层提取财会实体与实体间复杂的勾稽关系,为大模型优化微调提供数据层支持。图谱构建结果表明,GPT-4o mini能够成功从大量财务数据中提取丰富的知识五元组,并基于此构建财会知识图谱。最终,通过Neo4j技术实现知识图谱的可视化和查询功能。本研究证明大语言模型构建财会知识图谱具备可行性,能够显著提高知识图谱构建效率,为知识图谱的优化构建提供新思路,也为未来知识图谱融入大模型、优化模型性能提供基底数据支撑。
文摘通过自主搭建的石油焦颗粒堆积床导热性能测试实验装置开展了热态实验,探究了石油焦颗粒堆积床在不同粒度与升温速率下料层内外温度的变化规律。基于计算传热学原理,构建了圆柱管径向传热正问题模型,利用Levenberg-Marquardt算法反推导热系数,并与经典的等效导热系数模型(Bruggeman模型,Maxwell-Garnett模型,Kunii and Smith模型和Zehner-Bauer-Schlünder模型)进行了对比。结果表明,料层壁面与中心的温差随温度升高先增后减,随升温速率增大而增大,且随颗粒粒度减小而增加。基于导热反问题方法,获得了石油焦颗粒堆积床导热系数λ与温度T和等效粒径dp的数学关系式。引入等效粒度系数φ修正后的Kunii and Smith模型计算的导热系数及导热反问题求解的导热系数均与实验数据吻合度较高。研究成果可为罐式炉内石油焦堆积床传热行为的深入剖析提供重要的理论支撑。
